Potential of Industrial Solid Wastes as Energy Sources and Gaseous Emissions Evaluation in a Pilot Scale Burner (ES2008-54355)

Abstract

Industrially, many solid wastes can be classified as biomass and their usage reduces disposal costs. In this work, seven wastes from textile and food industries were characterized chemically and physically and the gaseous emissions resulting from the combustion of three of them (textile residues 3, TR3; coffee grounds; and a mixture of meat processing industry wastewater sludge and saw dust (1:9) in weight, SS1) in a pilot scale cyclone type combustor were measured. Their potential for utilization as energy sources was assessed by comparing the emissions to current legislation. Chemical properties showed that the volatile matter values of all biomass were high, which indicate that the solids burn rapidly. Some biomass presented high levels of sulfur and consequently high levels of SO2 emission when burned. The lower heating values ranged from 6.44 MJ kg−1 (dry and ash free, daf) to 22.93 MJ kg−1 (daf) and thermogravimetric analysis of the biomasses showed ignition temperatures and maximum burning rates, which were compared with other papers’ data. Four combustion tests were carried out in a cyclone type combustor and CO, CO2, NOx, CxHy, and SO2 were measured. Moisture content and particulate matter were also measured during the combustion tests and showed effective combustion conditions. Volatile organic compounds were analyzed by gas chromatography-mass spectrometry and their content values were expressed as total organic carbon (TOC), being all TOC emissions below the limits imposed by the regulations taken as reference. Gaseous emissions were compared with limits imposed by Brazilian and international current legislations, what showed that the usage of these biomasses as energy sources is possible; however, gas treatment would be required, especially if the solid presents high levels of sulfur and chlorine.